Liquid fuel injection nozzles



3 Sheets-Sheet l SePt- 9,1969 1'. PRIEDE ETAL LIQUID FUEL INJECTIONNOZZLES Filed aan. 9, 1967 SePt- 9, 1969 T. PRIEDE ETAL 3,465,969

LIQUID FUEL INJECTION NOZZLES Filed Jan. 9, 1967 5 Sheets-Sheet 2 Sept-9, 1969 T. PRIEDE ETAL 3,465,969

LIQUID FUEL INJECTION NOZZLES Filed Jan. 9, 1967 ,x 3 Sheets-Sheet 5United States Patent Office Patented Sept. 9, 1969 3,465,969 LIQUID FUELINJECTION NOZZLES Teodore Priede, Southampton, and Jan Wilkins, London,England, assignors to C.A.V. Limited, London, England Filed Jan. 9,1967, Ser. No. 607,931 Claims priority, applicati??1 /Great Britain,Jan. 7, 1966,

Int. Cl. B05b 1/30, 1/32 U.S. Cl. 239-533 1 Claim ABSTRACT OF THEDISCLOSURE This invention relates to liquid fuel injection nozzles ofthe type intended to be mounted in the body of an internal combustionengine and through which fuel is supplied to a combustion space of theengine by a fuel pump, whith the nozzle comprising a nozzle head havinga fuel discharge orifice, a valve member for controlling the fiow offuel through said orifice, and resilient means for biasing the valvemember towards a position in which the flow of fuel through the orificeis prevented.

The object of this invention is to provide such a nozzle in a form inwhich the emission of noise therefrom when in use, is minimized.

In the accompanying drawings:

FIGURE l is a sectional side elevation of one example of a liquid fuelinjection nozzle which may incorporate the invention and,

FIGURES 2, 3, 4, 5, 6 and 7 are views and an enlarged scale of part ofthe nozzle of FIGURE l and showing respectively various embodiments ofthe invention.

One example of a liquid fuel injection nozzle to which the invention maybe applied is shown in FIGURE l and in which there is provided anelongated body part 10 which is adapted to be mounted within a boreformed in the cylinder head of a compression ignition engine. Mounted onone end of the body part is a cylindrical nozzle head 11, the free endof which in use, extends into a combustion space of the engine.Moreover, in the free end of the nozzle head is formed a fuel dischargeorifice 12 and within the head is formed a cylindrical bore whichcontains a slidable valve member 13. Also formed in the nozzle head is aseating with which the valve member co-operates to prevent the iiow offuel through the orifice. Fuel is supplied to the orifice throughpassage 14 formed in the nozzle head and body part from a fuel supplypump and the arrangement is such that when fuel is supplied by the pumpthe valve member will be lifted from its seating to allow fuel to bedischarged into the combustion space through the orifice.

The valve member is urged onto its seating by a coiled compressionspring 15 which is accommodated in a chamber defined at the end of thebody part remote from the nozzle head. The spring acts upon the valvemember through a push rod and this is constituted by a spring abutment16 which is mounted upon a rod 17. As shown in FIGURE 2, the rod 17 isprovided with a blind bore 17a extending from the end of the rod remotefrom the abutment. Within the bore 17a are three struts defined by threesubstantially equal lengths of piano wire 18 which bear against the endof the 4bore and upon an extended portion of the valve member 13. Theend of the bore 17a adjacent the -valve member is enlarged and the tipof said extended portion enters therein but does not contact any part ofthe rod. The size of the bore in the rod is chosen to permit limitedbuckling of the wires under the applied load.

In a modification seen in FIGURE 3, the bore 17a is constant in diameterthroughout its length and the open end thereof is closed by a slidableplug 20. Furthermore, the end of he rod is rolled over to prevent theplug falling out. The operation of this modification is as described. Inthis example and the earlier example, the wires 18 are replaced by alarge number of wires 19.

In a further modification seen in FIGURE 4, the lengths of wire arereplaced by a plurality of Belleville washers 21 disposed Within thebore 17a in the rod 17 and which are slightly smaller in diameter thanthe bore. In use, the washers flatten out as the valve member movesagainst the action of the spring and in so doing, the edges thereofcontact the wall of the bore to limit the deflection.

In another modification seen in FIGURE 5, the bore i 17a is filledbehind the plug 20, with an insert 22 of a hard synthetic resin materialsuch for instance as nylon which can be compressed to a limited extentby a load applied thereto.

In a further modification shown in FIGURE 6, the bore 17a in the rod 17accommodates a bar 23 of rectangular section. The narrower edges of thebar are shaped in a manner complementary to the wall of the bore.Moreover, the opposite ends of the bar 23 are formed with integral plugs24, 25 respectively. The plug 24 is located at the inner end of the boreand is a tight fit while the plug 25 is a sliding fit in the bore.Moreover, the plug 25 is formed integrally with a cap 26 which engagesover the reduced end of the valve member 13. In use, the bar is able tobuckle a limited extent to provide the required resilience.

In a further modification shown in FIGURE 7 there is mounted within thebore 17a in the rod 17 a bar `27 complementary in shape to the 4bore andwhich is a sliding fit therein. Moreover, the outer end of the bore 17ais of enlarged diameter and accommodates a plug 28 formed integrallywith the bar 27. In this case the slight clearance between the bar 27and the wall of the bore enables the bar to be compressed slightly underthe applied load and thereby provides the required resilience.

It has been found that by using the constructions described theradiations of noise created by the impact of the valve member upon itsseating when the nozzle is in use is minimized. It will be appreciatedthat in the constructions shown in FIGURES 3, 4, 5, 6 and 7 relativemovement occurs between parts which are in contact with each other andit is thought that this also helps to reduce the noise emitted byproviding a measure of damping. Moreover, the rate of the resilientmember, that is to say, the force required to compress the member for aunit deflection, be it constituted by wires, rods, spring Washers or asynthetic resin insert, is arranged to be high as compared with the ratedefined in like manner, ofthe spring 15.

Having thus described our invention what We claim as new and desire tosecure by Letters Patent is:

1. A liquid fuel injection nozzle of the type intended to be mounted inthe body of an internal combustion engine and through which fuel issupplied to a combustion space of the engine, the nozzle comprising anozzle head having a fuel discharge orifice, a valve member forcontrolling the flow of fuel through said orifice and a spring forbiasing the valve member towards a position in which the flow of fuelthrough the orifice is prevented, with the valve member being movableagainst the action of said spring by fuel under pressure acting on thevalve member, the improvement comprising a push rod located between thespring and valve member, said push rod having a bore therein and aresilient means disposed within said bore and serving to transmit theforce exerted by said spring to said valve member, with the forcerequired to compress the resilient means for a unit of deection beinggreater than that of the spring and the deflection of said resilientmeans under load being limited.

References Cited UNITED STATES PATENTS 1,301,719 4/1919 Lloyd 239-5331,525,156 2/1925 Teufl 239-533 1,755,192 4/1930 Scott 239-533 2,750,9576/1956 Tavola 239-533 X 2,957,631 10/1960 Armstrong 23 9-533 3,124,3053/1964 Evans 29-533 3,175,771 3/1965 Breting 29-533 3,342,422 9/1967Millington etal 239-533 FOREIGN PATENTS 504,483 3/ 1927 Germany 736,7949/1955 Great Britain. 808,206 1/1959 Great Britain. 329,505 4/ 1958Switzerland.

EVERETI W. KIRBY, Primary Examiner U.S. Cl. XR.

